Pretty neat quirk. It only seems to be the case on the very last batches of original/phat DS systems, on the market at the same time as the DS Lite. The original DS models shipped with two brightness settings, and only two- "On" and "Off". The DSTwo, on compatible models, allows you to set variable brightness from within EOS/Real-time Menu by tapping the brightness icon- just like a DS Lite. It also, surprisingly, allows you to raise the brightness above the highest level the stock system software permits. Obviously, this won't turn your original DS into a DS Lite- by any stretch. The screen's still 2004-era quality, with the same washed-out colours as ever - but it is a marked improvement where the extra brightness is helpful, and a neat, unexpected bonus feature of the card. This only works on DS systems that shipped with Firmware v5 - essentially, just those released at the very end of the model's production run. Earlier model systems don't allow this to work- the necessary hardware just isn't available. It's the same sort of result you can get by flashing a late-revision FlashMe Lite firmware image on a v5 DS, but without the necessity of overwriting your system's firmware. To check whether your system is on a compatible (v5) firmware revision, just follow the standard steps- turn on the system with a DS cartridge inserted, open PictoChat, enter a Chat Room, then eject the cartridge while the system's still turned on. If both screens turn purple/magenta, your system is compatible with this- if not, you're out of luck. I assume that this will work on any other flashcart that allows brightness level adjustment from within its UI, as well- but I've only got a DSTWO to test it with.